Identification of Optimal Accelerometer Placement on Trains for Railway Switch Wear Monitoring via Multibody Simulation Provisionally Accepted

Zhicheng Hu^1* Albert Lau² Jian Dai³ Gunnstein T. Frøseth⁴

• ¹Department of Civil and Environmental Engineering, Norwegian University of Science and Technology, Norway
• ²Department of Civil and Environmental Engineering, Norwegian University of Science and Technology, Norway
• ³Department of Built Environment, Oslo Metropolitan University, Norway
• ⁴Department of Structural Engineering, Norwegian University of Science and Technology, Norway

Accelerometers play a crucial role in the railway industry, especially in track monitoring.Traditionally, they are placed on the railway tracks or often on bridges to monitor the health and condition of the infrastructure. Recently, there has been an increased focus on using regular trains to monitor the condition of railway infrastructure. Often, the sensors are placed based on certain assumptions without much scientific evidence or support. This paper utilizes the multibody simulation software GENSYS to identify the optimal placement of accelerometers on a passenger train for monitoring railway switch wear. Switch wear profiles were generated systematically and used as input for the simulations, studying acceleration at a total of 93 locations distributed among the wheelsets, bogies, and carbody. Based on both time and frequency domain analyses, optimal sensor locations were identified, generally close to the first bogie or wheelset at the leading carbody. Accelerations generated by the wheelset passing the switch can also be captured in the carbody, but it is important to note that these are several orders lower in magnitude compared to the acceleration on the wheelset. If accelerometers are to be placed in the carbody, correct sensitivity must be chosen, and a high-pass filter should be applied to capture the acceleration signals associated with switch wear. The study confirms that there is a direct correlation between the depth of switch wear and the magnitude of the acceleration. It remains effective even under various curve radii and train speeds.